Grounding 2 prong outlets ?

2019-10-17 7:53 pm
Okay so heres a question.  Im just learning about this kind of stuff, so bear with me.  A house with ungrounded outlets.  I was told an affordable option is to add a gfci outlet at the beginning of the circuit and that should do the trick economically.  Ideally sure, add a grounding conductor would be best.  BUT if its true about the gfci outlet trick...

1. Is this true?

2. Do the other outlets get brought up to 3 prong since they're grounded now?  

3. If you were looking at a house for someone, what would be the best advice on this situation if they had two prong outlets.

Also... bonus points if code refferences are included

回答 (3)

2019-10-17 8:53 pm
Ungrounded GFCIs do provide a lot of protection even when a ground is not installed.

The other outlets downstream of the GFCI will be protected by the GFCI, which is NOT the same as being grounded. You can change them over to 3-prong outlets for the sake of convenience.

Certain electronic devices (my son s EV charger comes to mind) require a ground to work. The GFCI will NOT provide a ground.

From my (admittedly old) 1993 NEC Handbook:

210-7(d)
"Ground fault circuit interruptor protected receptacles shall be provided where replacements are made at receptacle outlets that are required to be so protected elsewhere in this Code.

Exception: Where a grounding means does not exist in the receptacle enclosure, either a nongrounding or a ground-fault circuit-interruptor type of receptacle shall be used. A grounding conductor shall not be connected from the GFCI-type recptacle. Existing nongrounding-type receptacles shall be permitted to be replaced with grounding-type receptacles where supplied through a GFCI. These receptacles shall be marked, "GFCI protected."

Which is to say you can leave your two-prong outlets in place if need be. If there isn't a grounding wire provided in the boxes, you can change them out with 3-prong and protect them with the GFCI and add the little sticker that says GFCI to the outlet plate. Just don t run a grounding wire from the GFCI to the replaced outlets.

Good luck with it.
2019-10-18 7:13 am
I GFCI outlet DOES NOT add a ground. It provides similar protection by CUTTING power when there is the equivalent of a short to ground. If used for that purpose, ALL outlets downstream should be marked "No Equipment Ground".
That said, if the circuit has metal conduit, the conduit can be used as a ground in most cases.
Ideally, the wiring should be replaced with grounded wiring, but if you were going to do that, you wouldn't have asked the question.
2019-10-17 8:07 pm
Yes a GFCI will increase safety from shock. However it does not provide a ground. As far as code.. you are not required to add grounds in old. But any new circuits added would need to be with a ground.


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